Cleaning method, method of manufacturing semiconductor device, and substrate processing apparatus

ABSTRACT

There is provided a technique that includes: removing a deposit adhering to an inside of a process container by supplying a cleaning gas into the process container after performing a process of forming a film on a substrate in the process container, wherein the act of removing the deposit includes sequentially and repeatedly performing: a first process of supplying the cleaning gas into the process container until a predetermined first pressure is reached in the process container; a second process of stopping the supply of the cleaning gas and exhausting the cleaning gas and a reaction product generated by the cleaning gas remaining in the process container; and a third process of cooling an exhaust pipe that connects the process container and a vacuum pump, while maintaining a pressure inside the process container at a second pressure, which is lower than the first pressure, or lower.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a Bypass Continuation Application of PCTInternational Application No. PCT/JP2018/048482, filed Dec. 28, 2018,the disclosure of which is incorporated herein in its entirety byreference.

TECHNICAL FIELD

The present disclosure relates to a cleaning method, a method ofmanufacturing a semiconductor device, and a substrate processingapparatus.

BACKGROUND

In the related art, as a process of manufacturing a semiconductor deviceor an integrated circuit (hereinafter referred to as an electronicdevice or the like), a film-forming process for forming a film on asubstrate is often performed by supplying a precursor gas and a reactiongas to the substrate in a process chamber. When the film-forming processis performed, deposits may adhere to an inside of the process chamber.Thus, there is known a cleaning method that, after performing afilm-forming process, alternately repeats a step of cleaning an insideof a process chamber in which a substrate is processed by supplying acleaning gas into the process chamber and exhausting the cleaning gas inthe process chamber through an exhaust pipe and a step of cooling theexhaust pipe by maintaining a state where a flow of the cleaning gasinto the exhaust pipe is substantially stopped.

When the above-described cleaning process is performed, a waiting timefor cooling is generated in each step of cooling the exhaust pipe.Therefore, the cleaning process may be time-consuming.

SUMMARY

Some embodiments of the present disclosure provide a technique capableof improving a manufacturing throughput of an electronic device or thelike.

According to one embodiment of the present disclosure, there is provideda technique that includes: removing a deposit adhering to an inside of aprocess container by supplying a cleaning gas into the process containerafter performing a process of forming a film on a substrate in theprocess container, wherein the act of removing the deposit includessequentially and repeatedly performing: a first process of supplying thecleaning gas into the process container until a predetermined firstpressure is reached in the process container; a second process ofstopping the supply of the cleaning gas and exhausting the cleaning gasand a reaction product generated by the cleaning gas remaining in theprocess container; and a third process of cooling an exhaust pipe thatconnects the process container and a vacuum pump, while maintaining apressure inside the process container at a second pressure, which islower than the first pressure, or lower, wherein the third processcontinuously performs the act of cooling the exhaust pipe until atemperature of the exhaust pipe becomes equal to or lower than a firsttemperature, when the temperature of the exhaust pipe at the time oftransition from the second process to the third process is higher than asecond temperature that is higher than the first temperature, andwherein the third process terminates the act of cooling the exhaust pipeat a predetermined time without continuing the act of cooling theexhaust pipe until the temperature of the exhaust pipe becomes equal toor lower than the first temperature, when the temperature of the exhaustpipe is equal to or lower than the second temperature.

BRIEF DESCRIPTION OF DRAWINGS

The accompanying drawings, which are incorporated in and constitute apart of the specification, illustrate embodiments of the presentdisclosure.

FIG. 1 is a vertical cross-sectional view schematically showing anexample of a substrate processing apparatus suitably used in anembodiment of the present disclosure.

FIG. 2 is a schematic configuration diagram of a part of a substrateprocessing apparatus suitably used in an embodiment of the presentdisclosure, which is a horizontal cross-sectional view of a reactiontube.

FIG. 3 is a diagram illustrating a control part suitably used in anembodiment of the present disclosure.

FIG. 4 is a diagram showing gas supply timings in a film-formingsequence according to an embodiment of the present disclosure.

FIG. 5 is a diagram showing a processing timing, a gas supply timing, areaction chamber pressure and an exhaust pipe temperature in a firstcleaning according to an embodiment of the present disclosure.

FIG. 6 is a diagram showing a processing timing, a gas supply timing,and an exhaust pipe temperature in a first cleaning according to anembodiment of the present disclosure.

FIG. 7 is a flowchart showing a logic of a cleaning process according toan embodiment of the present disclosure.

DETAILED DESCRIPTION

Reference will now be made in detail to various embodiments, examples ofwhich are illustrated in the accompanying drawings. In the followingdetailed description, numerous specific details are set forth in orderto provide a thorough understanding of the present disclosure. However,it will be apparent to one of ordinary skill in the art that the presentdisclosure may be practiced without these specific details. In otherinstances, well-known methods, procedures, systems, and components havenot been described in detail so as not to unnecessarily obscure aspectsof the various embodiments.

Embodiments

In addition to shortening time for each cleaning performed every pluraltimes of performing a film formation, a cleaning cycle may be extendedto improve a manufacturing throughput of an electronic device or thelike. It may be effective to prevent a residue of cleaning from beingaccumulated to achieve the foregoing. Hereinafter, embodiments of thepresent disclosure will be described with reference to FIGS. 1 to 7.

(1) Configuration of Substrate Processing Apparatus

As shown in FIG. 1, a process furnace 202 includes a heater 207 as aheating means (heating mechanism). The heater 207 has a cylindricalshape and is vertically installed by being supported by a heater base(not shown) as a holding plate. The heater 207 also functions as anactivation mechanism (excitation part) that thermally activates(excites) a gas as described below.

Inside the heater 207, a reaction tube 203 that constitutes a reactioncontainer (process container) is arranged concentrically with the heater207. The reaction tube 203 is made of, for example, a heat-resistantmaterial such as quartz (SiO₂) or silicon carbide (SiC) and is formed tohave a ceiling with a lower end portion thereof opened and an upper endportion thereof closed by a flat wall body. A side surface of thereaction tube 203 includes a cylindrical portion 209 formed in acylindrical shape, a supply buffer 222 as a gas supply area and anexhaust buffer 224 as a gas exhaust area, which are provided at an outerwall of the cylindrical portion 209. A process chamber 201 is formedinside the cylindrical portion 209 of the reaction tube 203. The processchamber 201 is configured to be capable of processing wafers 200 assubstrates. Further, the process chamber 201 is configured to be capableof accommodating a boat 217 that can hold the wafers 200 in a horizontalposture in a state in which they are arranged in multiple stages alongan axial direction (that is, in a vertical direction) of the reactiontube 18.

The supply buffer 222 is formed so that a convex portion protrudesoutward from one side surface of the cylindrical portion 209. An outerwall of the supply buffer 222 is a part of an outer wall of the reactiontube 203 and has a diameter larger than an outer diameter of thecylindrical portion 209. The outer wall of the supply buffer 222 isformed in a circular arc shape concentrically with the cylindricalportion 209. The supply buffer 222 is formed to have a ceiling with alower end portion thereof opened and an upper end portion thereof closedby a flat wall body. The supply buffer 222 may serve as one or more of aspace that accommodates nozzles 340 a to 340 c described below, a ductthat allows a gas to flow therethrough, a buffer that regulates apressure to make a supply amount spatially uniform, and a preheaterconfigured to cause a thermal decomposition reaction of a gas to occurat an appropriate location. A gas supply slit (supply hole) 235configured to introduce a gas from a nozzle 340 a into the cylindricalportion 209 is formed at a boundary wall 252 which is a wall thatconstitutes a boundary between the supply buffer 222 and the inside ofthe cylindrical portion 209. The boundary wall 252 is a part of theoriginal cylindrical shape of the cylindrical portion 209, and an outersurface thereof constitutes a side surface portion facing the supplybuffer 222.

The exhaust buffer 224 is formed on the other side surface of thecylindrical portion 209 opposite to the one side surface on which thesupply buffer 222 is formed. The exhaust buffer 224 is arranged tosandwich a region of the process chamber 201 in which the wafers 200 areaccommodated, between the exhaust buffer 224 and the supply buffer 222.The exhaust buffer 224 is formed on the side surface of the cylindricalportion 209, at a location opposite to the side where the supply buffer222 is formed, to protrude outward. An outer wall of the exhaust buffer224 is a part of the outer wall of the reaction tube 203 and has adiameter larger than the outer diameter of the cylindrical portion 209.The outer wall of the exhaust buffer 224 is formed concentrically withthe cylindrical portion 209. The exhaust buffer 224 is formed to have aceiling with a lower end portion and an upper end portion thereof closedby flat wall bodies. An exhaust buffer slit (exhaust hole) 236 is formedat a boundary wall 254, which is a wall body that constitutes a boundarybetween the exhaust buffer 224 and the inside of the cylindrical portion209, to bring them into communication with each other. The boundary wall254 is a part of the cylindrical portion 209, and the outer side surfacethereof constitutes a side surface portion facing the exhaust buffer224. As an example, the supply buffer 222 and the exhaust buffer 224 maybe configured such that their internal shapes are substantially thesame.

The lower end of the reaction tube 203 is supported by a cylindricalmanifold 226. The manifold 226 is made of, for example, a metal such asnickel alloy or stainless steel, or is made of a heat-resistant materialsuch as quartz (SiO₂) or silicon carbide (SiC). A flange is formed at anupper end portion of the manifold 226, and the lower end of the reactiontube 203 is installed and supported on the flange. An airtight member220 such as an O-ring or the like is interposed between the flange andthe lower end portion of the reaction tube 203 to keep the inside of thereaction tube 203 airtight.

A seal cap 219 is airtightly attached to a lower end opening of themanifold 226 via the airtight member 220 such as the O-ring or the like.The seal cap 219 is configured to airtightly close the lower end openingof the reaction tube 203, that is, the opening of the manifold 226. Theseal cap 219 is made of, for example, a metal such as nickel alloy orstainless steel, and is formed in a disc shape. The seal cap 219 may beconfigured so that the outside thereof is covered with a heat-resistantmaterial such as quartz (SiO₂) or silicon carbide (SiC).

A boat support base 218 that supports the boat 217 is installed on theseal cap 219. The boat support base 218 is made of, for example, aheat-resistant material such as quartz or silicon carbide. The boatsupport base 218 functions as a heat insulating portion and serves as asupport body that supports the boat 217. The boat 217 is installedupright on the boat support base 218. The boat 217 is made of, forexample, a heat-resistant material such as quartz or silicon carbide.The boat 217 includes a bottom plate (not shown) fixed to the boatsupport base and a top plate (not shown) arranged above the bottomplate. The boat 217 has a configuration in which a plurality of columnsare installed between the bottom plate and the top plate. The boat 217holds a plurality of wafers 200. The wafers 200 are stacked in such astate that the wafers 200 are arranged in a horizontal posture with acertain distance being kept from one another in multiple stages alongthe axial direction of the reaction tube 203 with centers of the wafers200 aligned with one another and are supported by the columns of theboat 217.

A boat rotation mechanism 267 that rotates the boat is installed at theopposite side of the seal cap 219 from the process chamber 201. Therotation shaft 265 of the boat rotation mechanism 267 is connected tothe boat support base 218 through the seal cap 219. The boat rotationmechanism 267 rotates the boat 217 via the boat support base 218 torotate the wafers 200.

The seal cap 219 is vertically moved up or down by a boat elevator 115as an elevating mechanism installed outside the reaction tube 203,whereby the boat 217 can be loaded into or unloaded from the processchamber 201.

Nozzle support portions 350 a to 350 c that support nozzles 340 a to 340c are installed at the manifold 226 to be bent in an L shape andpenetrate the manifold 226. In the present embodiment three nozzlesupport portions 350 a to 350 c are installed. The nozzle supportportions 350 a to 350 c are made of, for example, a material such asnickel alloy or stainless steel. Gas supply pipes 310 a to 310 c thatsupply gases into the reaction tube 203 are connected to one ends of thenozzle support portions 350 a to 350 c on the side of the reaction tube203, respectively. Nozzles 340 a to 340 c are connected to the otherends of the nozzle support portions 350 a to 350 c, respectively. Thenozzles 340 a to 340 c are made of, for example, a heat-resistantmaterial such as quartz or SiC.

As an example, the nozzles 340 a to 340 c are installed to extend from alower side to an upper side in the supply buffer 222 along a lengthdirection (vertical direction) thereof. The nozzles 340 a to 340 c havegas supply holes 232 a to 232 c configured to discharge gasesrespectively. At least one of the gas supply holes 232 a to 232 c may beformed in the same number as the exhaust buffer slits 236 such that eachof the holes faces the center of the reaction tube 203. As describedabove, the three nozzles 340 a to 340 c are installed in the supplybuffer 222 and configured to be capable of supplying plural types ofgases into the process chamber 201.

In the process furnace 202 described above, the boat 217 is insertedinto the process chamber 201 while being supported by the boat supportbase 218 in a state in which a plurality of wafers 200 to bebatch-processed is stacked in multiple stages on the boat 217, and theheater 207 is configured to heat the wafers 200 inserted in the processchamber 201 to a predetermined temperature.

At the gas supply pipe 310 a, a first processing gas supply source (notshown) configured to supply a first processing gas, a mass flowcontroller (MFC) 241 a, which is a flow rate controller (flow ratecontrol part), and a valve 330 a, which is an opening/closing valve, areinstalled in this order from an upstream side. At the gas supply pipe310 b, a second processing gas supply source (not shown) configured tosupply a second processing gas, a mass flow controller (MFC) 241 b,which is a flow rate controller, and a valve 330 b, which is anopening/closing valve, are installed in this order from an upstreamside. At the gas supply pipe 310 c, a third processing gas supply source(not shown) configured to supply a third processing gas, a mass flowcontroller (MFC) 241 c, which is a flow rate controller, and a valve 330c which is an opening/closing valve, are installed in this order from anupstream side. A gas supply pipe 310 d configured to supply an inert gasand gas supply pipes 310 e and 310 f configured to supply a cleaning gasare connected to the gas supply pipes 310 a to 310 c on the downstreamside of the valves 330 a to 330 c, respectively. At the gas supply pipes310 d to 310 f, a fourth processing gas supply source (not shown) to asixth processing gas supply source (not shown) configured to supply afourth processing gas to a sixth processing gas, MFCs 241 d to 241 f,which are flow rate controllers (flow rate control parts), and valves330 d to 330 f, which are opening/closing valves, are installed in thisorder from an upstream side.

A first processing gas supply system mainly includes the gas supply pipe310 a, the MFC 320 a and the valve 330 a. The first processing gassupply source, the nozzle support portion 350 a and the nozzle 340 a maybe included in the first processing gas supply system. In addition, asecond processing gas supply system mainly includes the gas supply pipe310 b, the MFC 320 b and the valve 330 b. The second processing gassupply source, the nozzle support portion 350 b and the nozzle 340 b maybe included in the second processing gas supply system. In addition, athird processing gas supply system mainly includes the gas supply pipe310 c, the MFC 320 c and the valve 330 c. The third processing gassupply source, the nozzle support portion 350 c and the nozzle 340 c maybe included in the third processing gas supply system.

Further, a fourth processing gas supply system mainly includes the gassupply pipe 310 d, the MFC 320 d and the valve 330 d. The fourthprocessing gas supply source, the nozzle support portion 350 a and thenozzle 340 a may be included in the fourth processing gas supply system.In addition, a fifth processing gas supply system mainly includes thegas supply pipe 310 e, the MFC 320 e and the valve 330 e. The fifthprocessing gas supply source, the nozzle support portion 350 b and thenozzle 340 b may be included in the fifth processing gas supply system.Further, a sixth processing gas supply system mainly includes the gassupply pipe 310 f, the MFC 320 f and the valve 330 f. The sixthprocessing gas supply source, the nozzle support portion 350 c and thenozzle 340 c may be included in the sixth processing gas supply system.

When the term “processing gas” is used herein, it may include only thefirst processing gas, only the second processing gas, only the thirdprocessing gas, or all of them. Further, when the term “processing gassupply system” is used, it may include only the first processing gassupply system, only the second processing gas supply system, only thethird processing gas supply system, or all of them.

A precursor gas containing a predetermined element, for example, ahalosilane precursor gas containing Si as the predetermined element anda halogen element, is supplied from the first processing gas supplysource.

The halosilane precursor gas refers to a halosilane precursor in agaseous state, for example, a gas obtained by vaporizing a halosilaneprecursor staying in a liquid state at the room temperature and theatmospheric pressure, a halosilane precursor staying in a gaseous stateat the room temperature and the atmospheric pressure, and the like. Thehalosilane precursor refers to a silane precursor containing a halogengroup. The halogen group includes a chloro group, a fluoro group, abromo group, an iodo group and the like. That is, the halogen groupincludes halogen elements such as chlorine (Cl), fluorine (F), bromine(Br), iodine (I) and the like. It can be said that the halosilaneprecursor is a kind of halide. When the term “precursor” is used herein,it may mean “a liquid precursor staying in a liquid state”, “a precursorgas staying in a gaseous state”, or both.

As the halosilane precursor gas, it may be possible to use, for example,a precursor gas containing Si and Cl, that is, a chlorosilane precursorgas. As the chlorosilane precursor gas, it may be possible to use, forexample, a hexachlorodisilane (Si₂Cl₆, abbreviation: HCDS) gas. HCDSdoes not contain a hydrogen element in its composition. When using aliquid precursor such as HCDS or the like staying in a liquid state atthe room temperature and the atmospheric pressure, the liquid precursoris vaporized by a vaporization system such as a vaporizer or a bubblerand supplied as a precursor gas (HCDS gas).

From the second processing gas supply source, for example, a carbon(C)-containing gas is supplied as a reaction gas having a chemicalstructure (molecular structure) different from that of the precursorgas. As the carbon-containing gas, it may be possible to use, forexample, a hydrocarbon-based gas. It can be said that thehydrocarbon-based gas is a substance composed of only two elements, Cand H, and acts as a C source in a substrate processing processdescribed below. As the hydrocarbon-based gas, it may be possible touse, for example, a propylene (C₃H₆) gas.

From the second processing gas supply source, for example, an oxygen(O)-containing gas is supplied as a reaction gas having a chemicalstructure different from that of the precursor gas. Theoxygen-containing gas acts as an oxidizing gas, that is, an O source, inthe substrate processing process described later. As theoxygen-containing gas, it may be possible to use, for example, an oxygen(O₂) gas.

From the second processing gas supply source, for example, a boron(B)-containing gas such as borane or the like may be supplied as areaction gas having a chemical structure different from that of theprecursor gas.

From the third processing gas supply source, for example, a nitrogen(N)-containing gas is supplied as a reaction gas having a chemicalstructure different from that of the precursor gas. As thenitrogen-containing gas, it may be possible to use, for example, ahydrogen nitride-based gas such as an ammonia (NH₃) gas or the like. Thehydrogen nitride-based gas acts as a nitriding gas, that is, an N sourcein the substrate processing process described below.

From the fourth processing gas supply source, a fluorine-based gas issupplied as a cleaning gas. As the fluorine-based gas, it may bepossible to use, for example, a fluorine (F₂) gas.

From the fifth processing gas supply source, a reaction promoting gasthat promotes an etching reaction caused by the above-mentionedfluorine-based gas is supplied as a cleaning gas. As the reactionpromoting gas, it may be possible to use, for example, a nitric oxide(NO) gas.

From the sixth processing gas supply source, for example, a nitrogen(N₂) gas is supplied as an inert gas. The connection among the first tosixth process gas supply sources and the nozzles 340 a to 340 c is notlimited to the above-described method, and may be performed in variouscombinations. For example, the purge gas may be supplied to all nozzles,and the fluorine gas and the NO gas may be mixed with each other inadvance and supplied to one nozzle.

An exhaust port (or a connector) 230 is provided below the gas exhaustarea 224. The exhaust port 230 is connected to the exhaust pipe 232 influid communication. A vacuum pump 246 as an vacuum-evacuation device isconnected to the exhaust pipe 232 via a pressure sensor 245 as apressure detector configured to detect the pressure in the processchamber 201 and an APC (Auto Pressure Controller) valve 244 as apressure regulator. The process chamber 201 is configured to beevacuated such that a pressure in the process chamber 201 becomes apredetermined pressure (degree of vacuum). The exhaust pipe 232 on adownstream side of the vacuum pump 246 is connected to a waste gastreatment device (not shown) or the like. The APC valve 244 is anopening/closing valve that can be opened or closed to evacuate theinside of the process chamber 201 or to stop the evacuation of theinside of the process chamber 201. Further, a valve opening degree (aconductance) of the APC valve 244 can be adjusted to control an exhaustspeed and to regulate the pressure inside the process chamber 201. Anexhaust system mainly includes the exhaust pipe 232, the APC valve 244and the pressure sensor 245. The vacuum pump 246 may also be included inthe exhaust system.

A temperature sensor 238 as a temperature detector, which will bedescribed below, is installed in the reaction tube 203. By adjusting theelectric power supplied to the heater 207 based on temperatureinformation detected by the temperature sensor 238, a temperature insidethe process chamber 201 is controlled to have a desired temperaturedistribution. Further, a temperature sensor 231 a as a temperaturedetector configured to measure a temperature of the exhaust pipe 232 isdisposed in the exhaust pipe 232.

As shown in FIG. 2, in the gas supply area 222 and the gas exhaust area224, inner walls 248 and 250 are formed to divide an internal space ofeach area into a plurality of spaces. The inner walls 248 and 250 aremade of the same material as the reaction tube 203, and are made of, forexample, a heat-resistant material such as quartz (SiO₂) or siliconcarbide (SiC). In the present embodiment, each of the gas supply area222 and the gas exhaust area 224 has two inner walls and is divided intothree spaces.

The two inner walls 248 that partition the inside of the supply buffer222 are provided to partition the supply buffer 222 from a lower endside to an upper end side thereof and form three separate spaces. Thenozzles 340 a to 340 c are installed in the respective spaces of thesupply buffer 222. Since the nozzles 340 a to 340 c are respectivelyinstalled in independent spaces divided by the inner walls 248, it ispossible to prevent the processing gases supplied from the nozzles 340 ato 340 c from being mixed in the supply buffer 222. According to such aconfiguration, it is possible to prevent the processing gases frommixing with each other in the supply buffer 222 to form a thin film andprevent by-products from being generated in the supply buffer 222. Insome embodiments, the inner walls 248 may be provided divide the supplybuffer 222 from the lower end to the upper end thereof and form threespaces which are separated from each other.

The two inner walls 250 that partition the inside of the exhaust buffer224 are provided to partition the exhaust buffer 224 from the lower endside to the upper end side thereof and form three spaces which areseparated from each other. In some embodiments, the inner walls 250 maybe provided to partition the gas exhaust area 224 from the upper endthereof to a portion immediately above the exhaust port 230 and formthree spaces which are separated from each other.

Although the inner walls 250 may not always be provided for the exhaust,formation of the exhaust buffer 224 in a symmetrical shape with thesupply buffer 222 has merits of reducing a manufacturing cost andimproving a dimensional accuracy, a mechanical strength and atemperature uniformity.

As shown in FIG. 3, the controller 280, which is a control part, isconfigured as a computer including a CPU (Central Processing Unit) 121a, a RAM (Random Access Memory) 121 b, a memory device 121 c and an I/Oport 121 d. The RAM 121 b, the memory device 121 c and the I/O port 121d are configured to be capable of exchanging data with the CPU 121 a viaan internal bus 121 e. An input/output device 122 configured as, forexample, a touch panel or the like is connected to the controller 280.

The memory device 121 c includes, for example, a flash memory, an HDD(Hard Disk Drive), or the like. In the memory device 121 c, a controlprogram that controls an operation of the substrate processingapparatus, a process recipe in which the procedures and conditions ofthe substrate processing process described below are written, and thelike are readably stored. The process recipe is a combination thatallows the controller 280 to execute each procedure in the substrateprocessing process described below to obtain a predetermined result. Theprocess recipe functions as a program. Hereinafter, the process recipe,the control program and the like are collectively and simply referred toas a program. When the term “program” is used herein, it may includeonly the process recipe, only the control program, or both. The RAM 121b is configured as a memory area (work area) in which the program readby the CPU 121 a, data and the like are temporarily stored.

The I/O port 121 d is connected to the MFCs 241 a to 241 f, the valves330 a to 330 f, the pressure sensor 245, the APC valve 244, the vacuumpump 246, the heater 207, the temperature sensors 231 a and 238, theboat rotation mechanism 267, the boat elevator 115, and the like.

The CPU 121 a is configured to read the control program from the memorydevice 121 c and execute the control program thus read, and isconfigured to read the process recipe from the memory device 121 c inresponse to the input of an operation command from the input/outputdevice 122. The CPU 121 a is configured to control, according to thecontents of the read process recipe, the flow rate adjustment operationof various gases by the MFCs 241 a to 241 f, the opening/closingoperations of the valves 330 a to 330 f, the opening/closing operationof the APC valve 244, the pressure regulation operation by the APC valve244 based on the pressure sensor 245, the startup and stop of the vacuumpump 246, the temperature adjustment operation of the heater 207 basedon the temperature sensor 238, the rotation and rotation speedadjustment operation of the boat 217 by the boat rotation mechanism 267,the raising/lowering operation of the boat 217 by the boat elevator 115,and the like.

The controller 280 is not limited to being configured as a dedicatedcomputer, but may be configured as a general-purpose computer. Forexample, the controller 280 of the present embodiment may be configuredby providing an external storage device (for example, a magnetic tape, amagnetic disk such as a flexible disk or a hard disk, an optical disksuch as a CD or a DVD, a magneto-optical disk such as an MO or the like,a semiconductor memory such as a USB memory or a memory card, etc.) 123that stores the aforementioned program, and installing the program in ageneral-purpose computer through the use of the external memory device123. However, the means for supplying the program to the computer is notlimited to the case where the program is supplied via the externalstorage device 123. For example, the program may be supplied through theuse of communication means such as the Internet or a dedicated linewithout having to use the external memory device 123. The memory device121 c and the external memory device 123 are configured as acomputer-readable recording medium. Hereinafter, these are collectivelyand simply referred to as a recording medium. When the term “recordingmedium” is used herein, it may include only the memory device 121 c,only the external memory device 123, or both.

(2) Film-Forming Process

As one of processes of manufacturing a semiconductor device by using theabove-described substrate processing apparatus, a sequence example offorming a film on a substrate will be described with reference to FIG.4. In the following description, operations of the respective parts ofthe substrate processing apparatus are controlled by the controller 280.

In the film-forming sequence shown in FIG. 4, a silicon oxycarbonitridefilm (SiOCN film) as a film containing Si, O, C and N is formed on thewafer 200 as the substrate by performing a surface treatment step ofpretreating a surface of the wafer 200 by supplying an NH₃ gas as anitriding gas to the wafer 200, and then performing a cycle apredetermined number of times, the cycle including:

step 1 of supplying an HCDS gas as a precursor gas to the wafer 200;

step 2 of supplying a C₃H₆ gas as a carbon-containing gas to the wafer200;

step 3 of supplying an O₂ gas as an oxidizing gas to the wafer 200; and

step 4 of supplying the NH₃ gas as the nitriding gas to the wafer 200.

As an example, a cycle of non-simultaneously and sequentially performingsteps 1 to 4 may be performed a predetermined number of times (n times).Alternatively, some of steps 1 to 4 may be performed simultaneously. Inthe present embodiment, performing the cycle a predetermined number oftimes means performing the cycle once or a plurality of times.

In the present disclosure, the above-described film formation sequencemay be denoted as follows.

NH₃→(HCDS→C₃H₆→O₂→NH₃)×n→SiOCN film

When the word “wafer” is used herein, it may mean “wafer itself” or “alaminated body (aggregate) of a wafer and a predetermined layer or filmformed on the surface thereof”

In a case where carbon or oxygen may not be included in a composition,step 2 and step 3 may be omitted. In that case, an Si₃N₄ film may bedeposited.

Now, an outline of the film-forming process for one batch by using thesubstrate processing apparatus will be described.

(Wafer Charging and Boat Loading)

When a plurality of wafers 200 is charged to the boat 217 (wafercharging), as shown in FIG. 1, the boat 217 holding the plurality ofwafers 200 is lifted by the boat elevator 115 and loaded into theprocess chamber 201 (boat loading). In this state, the seal cap 219seals the lower end of the manifold 226 via the O-ring 220 b.

(Pressure Regulation and Temperature Adjustment)

An inside of the process chamber 201, that is, a space in which thewafers 200 exist, is vacuum-evacuated (depressurization-evacuated) bythe vacuum pump 246 to have a desired pressure (degree of vacuum). Atthis time, the pressure inside the process chamber 201 is measured bythe pressure sensor 245, and the APC valve 244 is feedback-controlledbased on the measured pressure information. The vacuum pump 246 ismaintained in a constantly operating state at least until the processingon the wafers 200 is completed.

Further, the wafers 200 in the process chamber 201 are heated by theheater 207 to have a desired film-forming temperature. At this time,supply of electric power to the heater 207 is feedback-controlled basedon the temperature information detected by the temperature sensor 238 sothat the inside of the process chamber 201 has a desired temperaturedistribution. By heating the wafers 200 in the process chamber 201 tothe film-forming temperature, the inner wall of the reaction tube 203,the surface of the boat 217, and the like are heated to the film-formingtemperature. The heating of the inside of the process chamber 201 by theheater 207 is continuously performed at least until the processing onthe wafers 200 is completed.

Further, the rotation of the boat 217 and the wafers 200 are started bythe boat rotation mechanism 267. The rotation of the boat 217 and thewafers 200 by the boat rotation mechanism 267 is continuously performedat least until the processing on the wafers 200 is completed.

(SiOCN Film Formation Step)

Next, a surface modification step described below is performed, and thenthe following four steps, that is, steps 1 to 4 are sequentiallyexecuted.

[Surface Modification Step] (NH₃ Gas Supply)

In this step, an NH₃ gas is caused to flow into the gas supply pipe 310c, and the valve 330 c is opened. The flow rate of the NH₃ gas isadjusted by the MFC 241 c. The NH₃ gas is supplied into the processchamber 201 from the nozzle 340 c heated to the film-formingtemperature, and is exhausted from the exhaust pipe 232. At this time,the wafers 200 are exposed to the NH₃ gas thermally activated. At thesame time, the valve 330 f is opened e, and an N₂ gas is caused to flowinto the gas supply pipe 310 f. The N₂ gas flowing through the gassupply pipe 310 f together with the NH₃ gas is supplied into the processchamber 201, and is exhausted from the exhaust pipe 232.

At this time, the APC valve 244 is appropriately adjusted so that thepressure in the process chamber 201 is set to a pressure falling withina range of, for example, 1 to 6000 Pa. The supply flow rate of the NH₃gas controlled by the MFC 241 a is set to a flow rate falling within arange of, for example, 100 to 10,000 sccm. The supply flow rate of theN₂ gas controlled by the MFC 241 c is set to a flow rate falling withina range of, for example, 100 to 10,000 sccm. A partial pressure of theNH₃ gas in the process chamber 201 is set to a pressure falling within arange of, for example, 0.01 to 5941 Pa. The time for which the NH₃ gasis supplied to the wafers 200, that is, gas supply time (irradiationtime) is set to a time falling within a range of, for example, 1 to 600seconds. The temperature of the heater 207 may be set such that thetemperature of the wafers 200 falls within a range of, for example, 250to 700 degrees C., specifically 300 to 650 degrees C., and morespecifically 350 to 600 degrees C. The NH₃ gas is thermally activatedunder the above conditions. In a case where the NH₃ gas is supplied bythermally activating the same, it is possible to generate a softreaction and to softly perform a surface modification described below.

By supplying the activated NH₃ gas to an outermost surface of the wafer200 (a base surface when forming the SiOCN film), the outermost surfaceof the wafer 200 is modified. As an example of the modification, NH₃ ora precursor may be adsorbed to the outermost surface of the wafer 200,dissociative adsorption may occur, the outermost surface of the wafer200 may be nitrided, or two or more of them may occur in parallel. Theoutermost surface of the wafer 200 subjected to the surface modificationhas a surface state in which HCDS is easily adsorbed and Si is easilydeposited in step 1 described below. That is, the NH₃ gas used in thesurface modification step acts as an adsorption/deposition promoting gasthat promotes adsorption and deposition of HCDS and Si on the outermostsurface of the wafer 200.

(Residual Gas Removal)

After the surface modification is completed, the valve 330 c is closedand the supply of the NH₃ gas is stopped. At this time, while keepingthe APC valve 244 opened, the inside of the process chamber 201 isvacuum-evacuated by the vacuum pump 246, and the NH₃ gas unreacted orcontributed to the surface modification, which remains in the processchamber 201, is substantially removed from the inside of the processchamber 201. At this time, the valve 330 f is kept opened to maintainthe supply of the N₂ gas into the process chamber 201. The N₂ gas actsas a purge gas, which makes it possible to enhance an effect of removingthe gas remaining in the process chamber 201 from the process chamber201.

In this context, the expression “substantially removed” means that thegas remaining in the process chamber 201 may not be completely removedand that the process chamber 201 may not be completely purged. In a casewhere an amount of the gas remaining in the process chamber 201 is verysmall, no adverse effect will occur in step 1 performed subsequently.The flow rate of the N₂ gas supplied into the process chamber 201 maynot be a large flow rate. For example, by supplying the N₂ gas in anamount similar to a volume of the reaction tube 203 (process chamber201), it is possible to perform purging to an extent that the adverseeffect does not occur in step 2. By not completely purging the inside ofthe process chamber 201 as described above, purging time can beshortened and consumption of the N₂ gas can be suppressed to a necessaryminimum level.

As the nitrogen-containing gas, in addition to the NH₃ gas, it may bepossible to use a hydrogen nitride-based gas such as a diazene (N₂H₂)gas, a hydrazine (N₂H₄) gas, an N₃H₈ gas or the like, or a gascontaining these compounds. As the inert gas, in addition to the N₂ gas,it may be possible to use, for example, a rare gas such as an Ar gas, aHe gas or the like.

[Step 1] (HCDS Gas Supply)

After the surface modification step is completed, an HCDS gas issupplied to the wafers 200 in the process chamber 201.

In this step, the opening/closing control of the valves 330 a and 330 fis performed in the same procedure as the opening/closing control of thevalves 330 c and 330 f in the surface modification step. The HCDS gas issupplied into the process chamber 201 through the gas supply pipe 310 aand the nozzle 340 a heated to the film-forming temperature. The supplyflow rate of the HCDS gas controlled by the MFC 241 a may be set to aflow rate falling within a range of, for example, 1 to 2000 sccm, andspecifically 10 to 1000 sccm. The pressure in the process chamber 201may be set to a pressure falling within a range of, for example, 1 to4000 Pa, specifically 67 to 2666 Pa, and more specifically 133 to 1333Pa. The time for which the HCDS gas is supplied to the wafers 200, thatis, the gas supply time (irradiation time) may be set to a time fallingwithin a range of, for example, 1 to 120 seconds, and specifically 1 to60 seconds. The temperature of the heater 207 may be set such that, asin the surface modification step, the temperature of the wafers 200falls within a range of, for example, 250 to 700 degrees C.,specifically 300 to 650 degrees C., and more specifically 350 to 600degrees C.

When the temperature of the wafers 200 exceeds 700 degrees C., the CVDreaction becomes too strong (an excessive vapor phase reaction occurs),whereby film thickness uniformity is likely to deteriorate and isdifficult to control. By setting the temperature of the wafers 200 to700 degrees C. or lower, a proper gas phase reaction is caused to occur,whereby the deterioration in the film thickness uniformity can besuppressed and the control thereof can be performed. In particular, bysetting the temperature of the wafers 200 to 650 degrees C. or lower,and further to 600 degrees C. or lower, the surface reaction becomesmore dominant than the gas phase reaction, whereby the film thicknessuniformity can be easily ensured and the control thereof can befacilitated.

Therefore, the temperature of the wafers 200 may be set to a temperaturefalling within a range of 250 to 700 degrees C., specifically 300 to 650degrees C., and more specifically 350 to 600 degrees C.

Other processing conditions are, for example, the same as the processingconditions of the surface modification step.

By supplying the HCDS gas to the wafers 200 under the above-describedconditions, an Si-containing film containing Cl, which has a thicknessof, for example, less than one atomic layer to several atomic layers isformed as a first layer on the outermost surface of the wafer 200. TheSi-containing layer containing Cl may be a physical adsorption layer ofHCDS, a chemical adsorption layer of HCDS, or both.

When the thickness of the first layer exceeds several atomic layers, themodification action in steps 3 and 4 described below does not reach theentire first layer. Further, a minimum value of the thickness of thefirst layer is less than one atomic layer. Therefore, the thickness ofthe first layer may be less than one atomic layer to several atomiclayers. Thus, the action of the modification reaction in steps 3 and 4described below can be relatively enhanced, and the time required forthe modification reaction can be shortened. The time required to formthe first layer in step 1 can also be shortened. As a result, it ispossible to shorten the process time per cycle and to shorten the totalprocess time.

(Residual Gas Removal)

After the first layer is formed, the valve 330 a is closed and thesupply of the HCDS gas is stopped. Then, by a processing proceduresimilar to the surface modification step, the HCDS gas unreacted orcontributed to the formation of the Si-containing layer containing Cland the reaction by-products, which remain in the process chamber 201,are removed from the process chamber 201. At this time, as in thesurface modification step, the gas and the like remaining in the processchamber 201 may not be completely removed.

As the precursor gas, in addition to the HCDS gas, it may be possible touse, for example, an inorganic precursor gas such as a dichlorosilane(SiH₂Cl₂, abbreviation: DCS) gas, a monochlorosilane (SiH₃Cl,abbreviation: MCS) gas, a tetrachlorosilane, that is, silicontetrachloride (SiCl₄, abbreviation: STC) gas, a trichlorosilane (SiHCl₃,abbreviation: TCS) gas, a trisilane (Si₃H₈, abbreviation: TS) gas, adisilane (Si₂H₆, abbreviation: DS) gas, a monosilane (SiH₄,abbreviation: MS) gas or the like, and an organic precursor gas such asa tetrakisdimethylaminosilane (Si[N(CH₃)₂]₄, abbreviation: 4DMAS) gas, atrisdimethylaminosilane (Si[N(CH₃)₂]₃H, abbreviation: 3DMAS) gas, abisdiethylaminosilane (Si[N(C₂H₅)₂]₂H₂, abbreviation: 2DEAS) gas, abis-tertiary-butylaminosilane (Sith[NH(C₄H₉)]₂, abbreviation: BTBAS) gasor the like.

[Step 2]

(C₃H₆ Gas Supply)

After step 1 is completed, a thermally activated C₃H₆ gas is supplied tothe wafers 200 in the process chamber 201.

In this step, the opening/closing control of the valves 330 b and 330 fis performed in the same procedure as the opening/closing control of thevalves 330 c and 330 f in the surface modification step. The C₃H₆ gas issupplied into the process chamber 201 through the gas supply pipe 310 band the nozzle 340 b heated to the film-forming temperature. The supplyflow rate of the C₃H₆ gas controlled by the MFC 241 b is set to a flowrate falling within a range of, for example, 100 to 10,000 sccm. Thepressure in the process chamber 201 is set to a pressure falling withina range of, for example, 1 to 6,000 Pa. The partial pressure of the C₃H₆gas in the process chamber 201 is set to a pressure falling within arange of, for example, 0.01 to 5941 Pa. The time for which the C₃H₆ gasis supplied to the wafers 200, that is, the gas supply time (irradiationtime) may be set to a time falling within a range of, for example, 1 to200 seconds, specifically 1 to 120 seconds, and more specifically 1 to60 seconds. Other processing conditions are, for example, the same asthe processing conditions in the surface modification step. The C₃H₆ gasis thermally activated under the above conditions.

At this time, the HCDS gas is not allowed to flow into the processchamber 201. Therefore, the C₃H₆ gas is supplied to the wafers 200 in anactivated state without causing a gas phase reaction. As a result, acarbon-containing layer (C-containing layer) is formed on the firstlayer, that is, the Si-containing layer containing Cl, which has beenformed on the wafer 200 in step 1. The C-containing layer may be a Clayer, a C₃H₆ adsorption layer, or both. The C-containing layer is alayer having a thickness of less than one molecular layer or less thanone atomic layer, that is, a discontinuous layer. Thus, a second layercontaining Si and C is formed on the outermost surface of the wafer 200.The second layer is a layer that includes an Si-containing layercontaining Cl and a C-containing layer.

The C-containing layer needs to be a discontinuous layer. When thesurface of the Si-containing layer containing Cl is entirely coveredwith the C-containing layer, Si does not exist on the surface of thesecond layer. As a result, the oxidation reaction of the second layer instep 3 described below, or the nitriding reaction of the third layer instep 4 described below may be difficult to occur. This is because N and0 are bonded to Si but is not easily bonded to C under the processingconditions described above. I, adsorption state of the C-containinglayer on the Si-containing layer containing Cl may be an unsaturatedstate, and Si may be exposed on the surface of the second layer to causea desired oxidation reaction or nitriding reaction in step 3 or step 4described below.

(Residual gas Removal)

After the second layer is formed, the valve 330 b is closed and thesupply of the C₃H₆ gas is stopped. Then, by the same processingprocedure as in the surface modification step, the C₃H₆ gas unreacted orcontributed to the formation of the C-containing layer and the reactionby-product, which remain in the process chamber 201, are removed fromthe process chamber 201. At this time, as in the surface modificationstep, the gas and the like remaining in the process chamber 201 may notbe completely removed.

As the carbon-containing gas, in addition to the C₃H₆ gas, it may bepossible to use a hydrocarbon-based gas such as an acetylene (C₂H₂) gas,an ethylene (C₂H₄) gas or the like.

[Step 3] (O₂ Gas Supply)

After step 2 is completed, a thermally activated O₂ gas is supplied tothe wafers 200 in the process chamber 201.

In this step, the opening/closing control of the valves 330 b and 330 fis performed in the same procedure as the opening/closing control of thevalves 330 c and 330 f in the surface modification step. The O₂ gas issupplied into the process chamber 201 through the gas supply pipe 310 band the nozzle 340 b heated to the film-forming temperature. The supplyflow rate of the O₂ gas controlled by the WC 241 b is set to a flow ratefalling within a range of, for example, 100 to 10,000 sccm. The pressurein the process chamber 201 is set to a pressure falling within a rangeof, for example, 1 to 6,000 Pa. The partial pressure of the O₂ gas inthe process chamber 201 is set to a pressure falling within a range of,for example, 0.01 to 5941 Pa. The time for which the O₂ gas is suppliedto the wafers 200, that is, the gas supply time (irradiation time) maybe set to a time falling within a range of, for example, 1 to 120seconds, and specifically 1 to 60 seconds. Other processing conditionsare, for example, the same as the processing conditions in the surfacemodification step. The O₂ gas is thermally activated under the aboveconditions.

At this time, neither the HCDS gas nor the C₃H₆ gas is allowed to flowinto the process chamber 201. Therefore, the O₂ gas is supplied to thewafers 200 in an activated state without causing a gas phase reaction.The O₂ gas supplied to the wafers 200 reacts with at least a part of thesecond layer containing Si and C (the layer including the Si-containinglayer containing Cl and the C-containing layer), which has been formedon the wafer 200 in step 2. Thus, the second layer is thermally oxidizedin a non-plasma manner and converted (modified) into a third layercontaining Si, O and C, that is, a silicon oxycarbide layer (SiOClayer). When forming the third layer, impurities such as Cl and the likecontained in the second layer constitute a gaseous substance containingat least Cl in the process of the modification reaction caused by the O₂gas. The gaseous substance is discharged from the inside of the processchamber 201. Thus, the third layer contains a smaller amount ofimpurities such as Cl or the like than the second layer.

At this time, the oxidation reaction of the second layer is notsaturated. For example, when the Si-containing layer containing Cl andhaving a thickness of several atomic layers is formed in step 1, and theC-containing layer having a thickness of less than one atomic layer isformed in step 2, at least a part of the surface layer (one atomic layerof the surface) is oxidized. In this case, in order not to oxidize theentire second layer, the oxidation is performed under the condition thatthe oxidation reaction of the second layer becomes unsaturated such thatthe second layer is not entirely oxidized.

At this time, in particular, the above-mentioned processing conditionsmay be adjusted by increasing a dilution rate of the O₂ gas with the N₂gas (reducing the concentration) or shortening the supply time of the O₂gas. Thus, uniformity can be obtained while making the oxidationreaction of the second layer unsaturated. The film-forming sequence ofFIG. 4 illustrates an example where the supply flow rate of the N₂ gassupplied in step 3 is made higher than the supply flow rate of the N₂gas supplied in other steps, thereby reducing the partial pressure ofthe O₂ gas and decreasing an oxidizing power.

By reducing the oxidizing power in step 3, it becomes easy to suppressdesorption of C from the second layer during the oxidation process.Since a bonding gas energy of an Si—O bond is larger than that of anSi—C bond, the Si—C bond tends to be broken when the Si—O bond isformed. Further, by reducing the oxidizing power in step 3, it ispossible to maintain the state where Si is exposed on the outermostsurface of the third layer, and to easily nitride the outermost surfaceof the third layer in step 4 described below. That is, when Si capableof bonding with N under the conditions of step 4 described below isallowed to exist on the outermost surface of the third layer, it becomeseasy to form an Si—N bond.

(Residual Gas Removal)

After the third layer is formed, the valve 330 b is closed and thesupply of the O₂ gas is stopped. Then, by the same processing procedureas in the surface modification step, the O₂ gas unreacted or contributedto the formation of the third layer and the reaction by-product, whichremain in the process chamber 201, are removed from the process chamber201. At this time, as in the surface modification step, the gas and thelike remaining in the process chamber 201 may not be completely removed.

As the oxidizing gas, in addition to the O₂ gas, it may be possible touse an oxygen-containing gas such as water vapor (H₂O), a nitric oxide(NO) gas, a nitrous oxide (N₂O) gas, a nitrogen dioxide (NO₂) gas, acarbon monoxide (CO) gas, a carbon dioxide (CO₂) gas, an ozone (O₃) gas,a hydrogen (H₂) gas+O₂ gas, an H₂ gas+O₃ gas), or the like.

[Step 4] (NH₃ Gas Supply)

After step 3 is completed, a thermally activated NH₃ gas is supplied tothe wafer s200 in the process chamber 201.

The processing procedure at this time is the same as the processingprocedure of the surface modification step described above. The time forwhich the NH₃ gas is supplied to the wafers 200, that is, the gas supplytime (irradiation time) may be set to a time falling within a range of,for example, 1 to 120 seconds, and specifically 1 to 60 seconds. Otherprocessing conditions are the same as the processing conditions of thesurface modification step described above. The NH₃ gas is thermallyactivated under the conditions described above.

At this time, the gas flowing into the process chamber 201 is thethermally activated NH₃ gas. The HCDS gas, the C₃H₆ gas and the O₂ gasare not allowed to flow into the process chamber 201. Therefore, the NH₃gas reaches the wafers 200 in an activated state without causing a gasphase reaction, and reacts with at least a part of the third layer (SiOClayer) formed on the wafer 200 in step 3. Thus, the third layer isthermally nitrided in a non-plasma manner and converted (modified) intoa fourth layer containing Si, O, C and N, that is, a siliconoxycarbonitride layer (SiOCN layer). When forming the fourth layer,impurities such as Cl and the like contained in the third layer form agaseous substance containing at least Cl in the process of themodification reaction with the NH₃ gas. The gaseous substance isdischarged from the inside of the process chamber 201. That is, theimpurities such as Cl and the like in the third layer are separated fromthe third layer by being extracted or desorbed from the third layer.Thus, the fourth layer contains a smaller amount of impurities such asCl and the like than the third layer.

Further, by supplying the activated NH₃ gas to the wafers 200, theoutermost surface of the third layer is modified in the process ofnitriding the third layer. The outermost surface of the third layersubjected to the surface modification process in the nitriding process,that is, the outermost surface of the fourth layer has surface state inwhich the HCDS is easily adsorbed and Si is easily deposited in the nextstep 1. That is, the NH₃ gas used in step 4 also acts as anadsorption/deposition promoting gas that promotes adsorption anddeposition of HCDS or Si on the outermost surface of the fourth layer(the outermost surface of the wafer 200).

At this time, the nitriding reaction of the third layer is notsaturated. For example, when the third layer having a thickness ofseveral atomic layers is formed in steps 1 to 3, nitriding is performedunder the condition that at least a part of the surface layer (oneatomic layer on the surface) is nitrided and the surface layer is notwholly nitrided.

(Residual Gas Removal)

After the fourth layer is formed, the valve 330 c is closed and thesupply of the NH₃ gas is stopped. Then, by the same processing procedureas in the surface modification step, the NH₃ gas unreacted orcontributed to the formation of the fourth layer and the reactionby-product, which remain in the process chamber 201, are removed fromthe process chamber 201. At this time, as in the surface modificationstep, the gas and the like remaining in the process chamber 201 may notbe completely removed.

(Performing a Predetermined Number of Times)

By performing a cycle that non-simultaneously performs the steps 1 to 4described above, one or more times (a predetermined number of times), aSiOCN film having a predetermined composition and a predetermined filmthickness can be formed on the wafer 200. The above cycle may berepeated multiple times. That is, it is preferable that the thickness ofthe SiOCN layer formed per cycle is set to be smaller than the desiredfilm thickness, and the above-described cycle is repeated a plurality oftimes until the film thickness reaches the desired film thickness.

(Purging and Atmospheric Pressure Restoration)

The valve 330 f is opened, and an N₂ gas is supplied into the processchamber 201 from the gas supply pipe 310 f and exhausted from theexhaust pipe 232. The N₂ gas acts as a purge gas. Thus, the inside ofthe process chamber 201 is purged, and the gas and reaction byproductremaining in the process chamber 201 are removed from the inside of theprocess chamber 201 (purging). Thereafter, the atmosphere in the processchamber 201 is replaced with an inert gas (inert gas replacement), andthe pressure in the process chamber 201 is returned to the atmosphericpressure (atmospheric pressure restoration).

(Boat Unloading and Wafer Discharging)

The boat elevator 115 lowers the seal cap 219 and opens the lower end ofthe manifold 226. Then, the processed wafers 200 are unloaded from thelower end of the manifold 226 to the outside of the reaction tube 203while being supported by the boat 217 (boat unloading). The processedwafers 200 are taken out from the boat 217 (wafer discharging).

(3) Cleaning Process

When the above film-forming process is performed, a deposit including athin film such as a SiOCN film or the like is accumulated on the innerwall of the reaction tube 203, the surface of the boat 217, and thelike. That is, the deposit including the thin film adheres to andaccumulates on surfaces of members in the process chamber 201 heated tothe film-forming temperature. A cleaning process is performed before theamount (thickness) of the deposit reaches a predetermined amount(thickness) before the deposit is separated or dropped.

The cleaning process is performed by executing a cleaning process inwhich a deposit including SiOCN and a by-product deposited on thesurfaces of the members in the process chamber 201 is removed through athermochemical reaction by supplying a fluorine-based gas as a cleaninggas from the nozzle 340 a heated to a cleaning temperature into theprocess chamber 201 heated to the cleaning temperature, and supplying areaction promoting gas as a cleaning gas from the nozzle 340 b heated tothe cleaning temperature.

In the cleaning process, an F2FLOW step as a first step of supplying acleaning gas into the reaction tube 203 and exhausting the cleaning gaswith the vacuum pump to maintain a predetermined first pressure, aVACUUM step as a second step of stopping the supply of the cleaning gasand exhausting the cleaning gas and the reaction product of the cleaninggas in the reaction tube 203, and an M.PUMP step as a third step ofcooling the exhaust pipe connecting the reaction tube 203 and the vacuumpump while maintaining the pressure inside the reaction tube 203 at asecond pressure lower than the first pressure or less, are sequentiallyand repeatedly performed N times (see FIG. 5).

Hereinafter, an example of the cleaning process will be described.

In the following description, operations of the respective parts of thesubstrate processing apparatus are controlled by the controller 280.

(Boat Loading)

The empty boat 217, i.e., the boat 217 not loaded with the wafers 200,is lifted by the boat elevator 115 and loaded into the process chamber201. In this state, the seal cap 219 seals the lower end of the manifold226 via the O-ring 220 b.

(Vacuum-Evacuation and Temperature Adjustment)

The inside of the process chamber 201 is vacuum-evacuated by the vacuumpump 246 to have a predetermined pressure or less (e.g., 10 Pa).Further, the inside of the process chamber 201 is heated by the heater207 to reach a specified temperature C. By heating the inside of theprocess chamber 201 to the specified temperature C, the inner wall ofthe reaction tube 203, the surfaces and insides (inner walls) of thenozzles 340 a to 340 c, the surface of the boat 217, and the like areheated to the specified temperature C. When the temperature in theprocess chamber 201 reaches the specified temperature C, the specifiedtemperature C is maintained until the cleaning process is completed.Then, rotation of the boat 217 by the boat rotation mechanism 267 isstarted. The rotation of the boat 217 is continuously performed untilthe cleaning process is completed. However, the boat 217 may not berotated.

(Cleaning process)

Thereafter, as shown in FIG. 5, the following three steps, that is, theF2FLOW step, the VACUUM step and the M.PUMP process are sequentiallyexecuted. As will be described later, time required for the F2FLOW stepand the VACUUM step is fixed except during an emergency such as anemergency stop or the like, but time required for the M.PUMP step may beextended by an additional waiting time.

[F2FLOW Step]

In the F2FLOW step, an F₂ gas is introduced into the process chamber 201from the nozzle 340 a by opening the valve 330 d. Further, an NO gas maybe introduced from the heated nozzle 340 b by opening the valve 330 e.At this time, as shown in the upper graph of FIG. 5, the MFCs 241 d and241 e are controlled such that the gases are introduced at apredetermined flow rate (e.g., 10 slm). Further, the APC valve 244 isappropriately adjusted to maintain the pressure inside the processchamber 201 at a first cleaning pressure, for example, 100 Torr.

At this time, the N₂ gas may be caused to flow from the gas supply pipe310 f or the like to dilute the F₂ gas and the NO gas, respectively. Allthe nozzles may be constantly supplied with a minimum amount (e.g., 1sccm) of N₂ gas to keep the inside of the gas supply pipe clean orprotect the same. The flow rate of the N₂ gas depends on the flow ratesof other gases flowing together from the same supply pipe, therebypreventing a backflow. The flow rate of the N₂ gas from the nozzle iscontrolled to be constant, and is, for example, 1 slm or less in total.Separately from this, a shaft purge gas that protects the rotation shaft265 and prevents adhesion of a by-product to the low temperature portionmay be supplied at a predetermined flow rate (e.g., 1 slm or less) andintroduced into the process chamber 201. At the beginning of the F2FLOWstep, the pressure is below a target value and, therefore, the APC valve244 may be fully closed. When the pressure inside the process chamber201 reaches 100 Torr, the APC valve 244 performs pressure control whilechanging its opening degree. As a result, the pressure is changed asshown in the middle graph of FIG. 5.

When the cleaning gas passes through the process chamber 201 and isexhausted from the exhaust pipe 232, the cleaning gas makes contact withthe members inside the process chamber 201, for example, the inner wallof the reaction tube 203, the surfaces of the nozzles 340 a to 340 c,the surface of the boat 217, and the like. Then, the cleaning gas andthe deposit chemically react with each other. The deposit is vaporizedand removed by being changed to a substance (product gas) having a lowvapor pressure. Through this reaction, q total number of moles of a gascan be increased, for example, as in the reaction described below.

F₂+2NH₄Cl→2NH₃+2HF+Cl₂

The reaction caused by this cleaning gas is usually an exothermicreaction, and a mixture of the unreacted cleaning gas, the N₂ gas andthe product gas flowing into the exhaust pipe 232 has a hightemperature. The temperature of the exhaust pipe 232 on the upstreamside of the APC valve 244 (on the side of the process chamber 201) isshown in the lower graph of FIG. 5. The temperature of the exhaust pipe232 increases in conjunction with the increase in pressure due to theintroduction of the cleaning gas.

[VACUUM Step]

When a preset gas supply time has elapsed from the start of the F2FLOWstep, the valves 330 d and 330 e are closed to terminate the F2FLOW stepand start the VACUUM step. In the VACUUM step, the supply of thecleaning gas into the process chamber 201 is stopped, the APC valve 244is kept in an open state, and the cleaning gas or the like in theprocess chamber 201 is exhausted through the exhaust pipe 232. As shownin FIG. 5, the pressure inside the process chamber 201 is controlled bythe APC valve 244 to gradually decrease at a predetermined rate (e.g.,−2000 Pa/s). The VACUUM step is completed at a fixed time because thepressure is reduced from a predetermined pressure (100 Torr) at apredetermined rate. Alternatively, it is possible to give extension totime to reach 10 Pa such that the low pressure is maintained for apredetermined time.

In the VACUUM step, the gas supply pipe 310 f or the like may be openedto supply the N₂ gas into the process chamber 201 at a predeterminedflow rate, for example, at the same flow rate as in the F2FLOW step.Execution time of the VACUUM step may be determined by a criterion thatcauses a suitable gas flow or pressure fluctuation in the processchamber 201. In this step, a pressure change rate is higher than that inthe F2FLOW step. Therefore, a strong flow toward the exhaust port 230 isgenerated in almost the entire process chamber 201. Diffusion ispromoted by this convection (advection), and the cleaning reaction iseasier to spread to every corner. It is known that diffusion(dispersion) is greatly promoted when a gas flows in the process chamber201 under a condition that a velocity gradient (vortex) or a turbulentflow is generated.

If a pressure reduction rate is too high, the cleaning time isshortened, whereby the cleaning effect may be rather reduced andparticles may be generated. The thickness of the deposit layer to becleaned is not necessarily uniform in the process chamber 201, and maybe uneven depending on the chemical reaction and the substance transportconditions (Reynolds number and the like) when the deposit layer isdeposited. Accordingly, a gas flow velocity distribution may be formedto reproduce the same etching unevenness as unevenness at thedeposition. The flow rate of the N₂ gas may be set for that purpose.

When the F2FLOW step and the VACUUM step described above are performed,the cleaning gas or the like supplied into the process chamber 201 flowsinto the exhaust pipe 232 in a concentrated manner, and the cleaning gasof a high concentration flows through the exhaust pipe 232 at a highflow rate. The temperature of the exhaust pipe 232 rises as shown inFIG. 5 because the exhaust pipe 232 is exposed to a higher temperaturegas due to the intense cleaning reaction and because the cleaningreaction also occurs intensely on the inner surface of the exhaust pipe232. When the temperature of the exhaust pipe 232 rises to atemperature, for example, higher than 200 degrees C., even in a casewhere the exhaust pipe 232 is made of, for example, an alloy havingexcellent heat resistance and corrosion resistance such as Hastelloy(registered trademark) or the like, the exhaust pipe 232 may be corrodedand may be damaged. Alternatively, a seal member that seals a joint ofthe exhaust pipe 232 may be deteriorated. Therefore, a criticaltemperature may be set to perform an operation such that the criticaltemperature is not exceeded. The pressure reduction rate of the F2FLOWstep is also limited in this respect.

[M.PUMP Step]

When the VACUUM step is completed, in the M.PUMP process, the exposureof the cleaning gas and the reaction by-product to the exhaust pipe 232is made less than that in the F2FLOW step and the VACUUM step whilemaintaining the pressure inside the reaction pipe 203 at a secondpressure lower than the first pressure or less. Thus, the exhaust pipe232 heated in the VACUUM step and the M.PUMP step is cooled (naturalcooling). For example, the APC valve 244 is fully opened and the insideof the reaction tube 203 is maintained at an ultimate pressure or apressure of 10 Pa or less. At this time, the valve 330 f or the like isclosed or the MFC 241 f is controlled to stop the supply of the N₂ gasinto the exhaust pipe 232 or limit the supply of the N₂ gas such thatthe ultimate pressure does not increase excessively. A modest amount ofN₂ gas helps reduce the partial pressure of the reaction product tobelow a parallel vapor pressure.

The temperature of the exhaust pipe 232 may rise for a while even afterentering the M.PUMP step because of the delay in heat transfer. However,the temperature of the exhaust pipe 232 begins to drop soon. The M.PUMPstep is continued for at least a predetermined time while measuring thetemperature of the exhaust pipe 232 by the temperature sensor 231 a. Ina case where the highest temperature measured in the M.PUMP step at thattime is equal to or lower than a specified temperature B, the M.PUMPstep is terminated and the process proceeds to the F2FLOW step of thenext cycle. In a case where the highest temperature exceeds thespecified temperature B, the M.PUMP step is continued until thetemperature of the exhaust pipe 232 drops to below a specifiedtemperature A.

The specified temperature A (first temperature) is a temperature betweena normal temperature (room temperature) and a critical temperature (atemperature at which the exhaust pipe 232 undergoes corrosion), and isset to a temperature which is set the critical temperature is notexceeded even when the F2FLOW step and the VACUUM step of the second andsubsequent cycles are started from that temperature. The specifiedtemperature A is appropriately determined according to variousconditions such as the material, structure, heat capacity and heatradiation efficiency of the exhaust pipe 232, the type and flow rate ofthe cleaning gas, the processing temperature, and the like. When theabove-mentioned critical temperature is 200 degrees C., the specifiedtemperature A may be set to a temperature falling within a range of, forexample, 60 degrees C. to 90 degrees C.

When the cycle including the F2FLOW step, the VACUUM step and the M.PUMPstep is sequentially repeated, the byproduct is removed and the chemicalreaction is decreased, whereby the temperature rise in the exhaust pipedecreases. Accordingly, the temperature does not exceed the criticaltemperature without waiting for the temperature to drop to the specifiedtemperature A (see FIG. 6). The waiting for the temperature to drop atthis time would be a waste of time.

Therefore, in the present embodiment, when the temperature is equal toor lower than the specified temperature B during the M.PUMP step, theM.PUMP step is terminated without waiting for the temperature decrease.

For example, the specified temperature B (second temperature) may be setto be higher than the specified temperature A by a predeterminedtemperature a. The specified temperature B is appropriately determinedin accordance with various conditions such as the material, structure,heat capacity, heat dissipation efficiency of the exhaust pipe 232, thetype and flow rate of the cleaning gas, the processing temperature andthe like, and is determined so as not to exceed the critical temperaturein the next F2FLOW step and VACUUM step. Furthermore, the temperature ofthe exhaust pipe 232 to be compared with the specified temperature B maybe measured once at the beginning of (immediately before) the M.PUMPstep as shown in FIG. 7, or may be measured throughout the cycle.

In the M.PUMP step, the valve 330 f may be opened to allow the N₂ gas toflow into the exhaust pipe 232. In this case, the N₂ gas acts as acooling gas (cooling medium), and may accelerate the cooling of theexhaust pipe 232. At this time, the N₂ gas may be directly supplied intothe exhaust pipe 232. In this case, for example, a port configured tosupply the N₂ gas may be provided on the upstream side of the exhaustpipe 232, a supply pipe configured to supply the N₂ gas may be connectedto the port, and the N₂ gas may be supplied into the exhaust pipe 232via this supply pipe and the port. By directly supplying the N₂ gas intothe exhaust pipe 232 without going through the high-temperature processchamber 201, it is possible to further promote the cooling of theexhaust pipe 232.

[Performing a Predetermined Number of Times]

Thereafter, the F2FLOW step, the VACUUM step and the M.PUMP step aresequentially repeated a predetermined number of times to perform thecleaning process. By alternately repeating the F2FLOW step, the VACUUMstep and the M.PUMP step, it is possible to properly perform theabove-described deposit removal process while maintaining thetemperature of the exhaust pipe 232 below the critical temperature.

As an example, the processes of steps S100 to S110 are sequentiallyrepeated a predetermined number of times (e.g., 30 times) as in theflowchart shown in FIG. 7.

First, the F2FLOW step is performed in step S100. Then, the VACUUM stepis performed in step S102. When the VACUUM step is completed, it isdetermined in step S104 whether the temperature of the exhaust pipe 232measured by the temperature sensor 231 a is equal to or lower than thespecified temperature B.

When the temperature of the exhaust pipe 232 measured by the temperaturesensor 231 a is equal to or lower than the specified temperature B, instep S106, the M.PUMP step is completed at a predetermined time. Theprocess returns to step S100 and goes to the next F2FLOW step. Atemperature rise width of the exhaust pipe 232 in the VACUUM stepmonotonically decreases depending on the number of repetitions of thecycle. Therefore, once branched to step S106, it is expected to bebranched to step S106 in the subsequent cycles, whereby each of thecycles is repeated in a fixed time pattern.

On the other hand, in step S104, when the temperature of the exhaustpipe 232 measured by the temperature sensor 231 a is higher than thespecified temperature B, the M.PUMP step is performed for apredetermined time in step S108. Thereafter, in step S110, after waitinguntil the temperature of the exhaust pipe 232 measured by thetemperature sensor 231 a becomes equal to or lower than the specifiedtemperature A, the process returns to step S100 and proceeds to the nextF2FLOW step. The waiting in step S110 is performed while continuing theM.PUMP step started in step S108.

(4) Modification of Cleaning Process

The cleaning process in the present embodiment is not limited to theabove-mentioned aspect, and may be modified as in the followingmodifications.

(Modification 1)

When the F2FLOW step is performed, the pressure in the process chamber201 may be changed by intermittently supplying the N₂ gas into theprocess chamber 201 while continuously supplying the F₂ gas and the NOgas into the process chamber 201. That is, in the F2FLOW step, thevalves 330 d and 330 e may be kept open, and at this time, theopening/closing operation of at least one of the valves 330 d and 330 emay be repeated. Also in this case, it is possible to improve anefficiency of removing the deposit from the inside of the processchamber 201.

(Modification 2)

When performing the F2FLOW step, it may be possible to perform a step ofsupplying and containing the F₂ gas and the NO gas into the processchamber 201 and a step of maintaining the state in which the F₂ gas andthe NO gas are contained in the process chamber 201.

Furthermore, by supplying and confining the F₂ gas and the NO gas intothe process chamber 201, it becomes possible to prevent the F₂ gas andthe NO gas from being discharged from the process chamber 201 withoutcontributing to the cleaning. The surface chemical reaction at this timeis rate-limited to diffusion. If time is taken, the F₂ gas and the NOgas are spread over the entire area of the process chamber 201, whichmakes it easy to perform cleaning with little unevenness. Furthermore,the APC valve 244 is substantially closed while maintaining the state inwhich the cleaning gas is contained in the process chamber 201.Therefore, it is possible to cool the exhaust pipe 232.

When the opening of the APC valve 244 is controlled in the cleaningprocess, the opening degree may increase or decrease (oscillate)depending on the characteristics of the PID control. However, there is asecondary effect of changing the gas flow and promoting the substancemovement. Alternatively, the vibration may be intentionally increased,or the APC valve 244 may be controlled to alternately repeat a fullclosing operation and a full opening operation. Further, the APC valve244 may be opened slightly even when the pressure is lower than a targetvalue and the APC valve 244 is to be fully closed, thereby reducingwearing of the valve.

(5) Effects of the Present Embodiment

According to the present embodiment, one or more of the followingeffects may be obtained.

(a) In the cleaning process, when the temperature of the exhaust pipe atthe transition from the VACUUM step to the M.PUMP step is higher thanthe specified temperature B higher than the specified temperature A, thecooling is continued until the temperature of the exhaust pipe becomesthe specified temperature A or lower. When the temperature of theexhaust pipe is equal to or lower than the specified temperature B, thecooling of the exhaust pipe is completed at a predetermined time withoutcontinuing the cooling until the temperature of the exhaust pipe becomesequal to or lower than the specified temperature A. Therefore, it ispossible to shorten the time for which the cooling of the exhaust pipeis waited. The specified temperature A is not limited to a single setvalue, and a plurality of set values may be used according to theprogress (the number of repetitions) of the cleaning process.

(b) In the cleaning process, the F2FLOW step and the VACUUM step ofcleaning the inside of the process chamber 201 and the M.PUMP step ofcooling the exhaust pipe 232 are sequentially repeated. Thus, atreatment process or the cleaning process can be appropriately performedwhile maintaining the temperature of the exhaust pipe 232 at atemperature equal to or lower than the specified temperature B, that is,the temperature below a critical temperature.

(c) As described above, when a gas such as HCDS gas or the like having alarge number of Cl contained in one molecule is used as the precursorgas, a reaction by-product such as NH₄Cl is easily generated, and theamount of the reaction by-product deposited inside the exhaust pipe 232tends to increase. Further, even when the exhaust pipe 232 is configuredas a pipe such as a bellows pipe, having an uneven structure on an innerwall thereof, the amount of reaction by-product adhering to the insideof the exhaust pipe 232 tends to increase. Therefore, in these cases,the temperature of the exhaust pipe 232 is easily increased byperforming the cleaning process. The present embodiment in which theM.PUMP step is performed at the above-described timing has greatsignificance in such cases.

(d) By merely changing the cleaning recipe so that the M.PUMP step isperformed at the above-described timing, the effects described above maybe obtained. That is, in the present embodiment, it is not necessary tomake the configuration of the exhaust system of the substrate processingapparatus complicated by, for example, separately providing a coolingdevice such as a chiller unit or the like configured to cool the exhaustpipe 232. Therefore, it is possible to avoid an increase in amanufacturing cost, a remodeling cost and a maintenance cost of thesubstrate processing apparatus. Further, the electric power to operatethe cooling device is also unnecessary. Therefore, it is possible toavoid an increase in the electric power consumption of the substrateprocessing apparatus, i.e., an operating cost.

(e) In the M.PUMP step, the N₂ gas as a cooling gas is supplied into theexhaust pipe 232 to forcibly cool the exhaust pipe 232. This makes itpossible to improve the cooling efficiency of the exhaust pipe 232 andto shorten the execution time of the M.PUMP step. As a result, the timerequired for the cleaning process, that is, downtime of the substrateprocessing apparatus can be shortened to improve the productivity of thesubstrate processing apparatus.

(f) By sequentially repeating the F2FLOW step, the VACUUM step and theM.PUMP step to repeatedly change the pressure in the process chamber201, it is possible to increase the efficiency of removing the depositfrom the inside of the process chamber 201. As a result, the timerequired for the cleaning process, that is, the downtime of thesubstrate processing apparatus can be shortened to improve theproductivity of the substrate processing apparatus.

(g) In the cleaning process, by using the F₂ gas and the NO gas, thatis, by using the mixed gas obtained by adding the NO gas to the F₂ gas,it is possible to increase the etching rate of the deposit and toefficiently carry out the cleaning of the inside of the process chamber201. In addition, by using the F₂ gas and NO gas in the cleaningprocess, even when the processing conditions such as the temperature(cleaning temperature) in the process chamber 201 are set to theconditions on the low temperature side, it is possible to perform thecleaning in the process chamber 201 at a practical speed. As a result,it is possible to suppress the etching damage to the quartz member inthe process chamber 201 and to more reliably avoid the corrosion of theexhaust pipe 232.

Other Embodiments of the Present Disclosure

The embodiments of the present disclosure have been specificallydescribed above. However, the present disclosure is not limited to theabove-described embodiments, and various modifications may be madewithout departing from the spirit of the present disclosure.

For example, the exhaust pipe 232 may be provided with a sub-heater(jacket heater) as a heating mechanism. By heating the exhaust pipe 232with the sub-heater when performing the above-described film-formingprocess, it becomes possible to suppress adhesion of the reactionby-product to the inside of the exhaust pipe 232. However, even when theexhaust pipe 232 is heated by the sub-heater when performing thefilm-forming process, it is difficult to completely prevent the reactionby-product from adhering to the inside of the exhaust pipe 232. Thus,the problem described above may occur during the cleaning process. Theexhaust pipe 232 is not heated by the sub-heater when performing thecleaning process described above.

Further, for example, in the above-described embodiments, there has beendescribed the example in which the F₂ gas as a fluorine-based gas andthe NO gas as a reaction promoting gas are used in combination as thecleaning gas. However, the present disclosure is limited thereto. Thatis, as the cleaning gas, a fluorine-based gas such as an F₂ gas, achlorine trifluoride (ClF₃) gas, a nitrogen trifluoride (NF₃) gas or ahydrogen fluoride (HF) gas may be used alone, or a gas obtained bymixing the above gases in any combination may be used. In addition, asthe reaction promoting gas, it may be possible to use an H₂ gas, an O₂gas or an NH₃ gas. Further, other nitrogen oxide gases such as an N₂Ogas, an NO₂ gas or the like may be used as the reaction promoting gas.

Further, for example, in the above-described embodiments, there has beendescribed the example in which the SiOCN film is formed on the wafer 200by the film-forming sequence shown in FIG. 4, that is, the film-formingsequence denoted below, and then the inside of the process chamber 201is cleaned.

NH₃→(HCDS→C₃H₆→O₂→NH₃)×n→SiOCN film

However, the present disclosure is not limited to the aspects describedabove. That is, the cleaning process described above may be suitablyimplemented even after silicon-based insulating films such as a SiOCNfilm, a silicon carbonitride film (SiCN film), a silicon oxynitride film(SiON film), a silicon nitride film (SiN film), a siliconborocarbonitride film (SiBCN film), a silicon boronitride film (SiBNfilm) and the like are formed on the wafer by the film-forming sequencesdenoted below.

NH→(CH→HCDS→CH→O→NH)×n→SiOCN film

NH₃→(HCDS→C₃H₆→NH₃→O₂)×n→SiOCN film

NH₃→(HCDS→C₃H₆→NH₃)×n→SiCN film

NH₃→(HCDS→NH₃→O₂)×n→SiON film

NH₃→(HCDS→NH₃)×n→SiN film

NH₃→(HCDS→C₃H₆→BCl₃→NH₃)×n→SiBCN film

NH₃→(HCDS→BCl₃→NH₃)×n→SiBN film

The processing procedure and processing conditions in each step of thesefilm-forming sequences may be, for example, the same as the processingprocedures and processing conditions in the above-described embodiments.In the step of supplying the BCl₃ gas to the wafer 200, the BCl₃ gas isallowed to flow from the gas supply pipe 310 b. Further, the supply flowrate of the BCl₃ gas controlled by the MFC 241 b is set to a flow ratefalling within a range of, for example, 100 to 10000 sccm. Otherprocessing conditions are, for example, the same as those in step 2 ofthe film-forming sequence shown in FIG. 4.

A process recipe (a program in which the processing procedures andprocessing conditions of the film-forming process are described) usedwhen forming these various thin films, and a cleaning recipe (a programin which the processing procedures and processing conditions of thecleaning process are described) used when removing a deposit includingthese various thin films may be individually provided (in a pluralnumber) according to the contents (a type of the thin film to be formedor removed, a composition ratio, a film quality, a film thickness, andthe like) of the film-forming process and the cleaning process. Whenstarting the substrate processing process, an appropriate recipe may beselected from a plurality of recipes according to the contents of thesubstrate processing process. Specifically, a plurality of recipesindividually provided according to the contents of the substrateprocessing process may be stored (installed) in advance in the memorydevice 121 c included in the substrate processing apparatus via anelectric communication line or a recording medium (external memorydevice 123) in which the recipes are stored. Then, when starting thefilm-forming process or the cleaning process, the CPU 121 a included inthe substrate processing apparatus may select an appropriate recipe fromthe plurality of recipes stored in the memory device 121 c according tothe contents of the substrate processing process. With such aconfiguration, it becomes possible to form thin films of various filmtypes, composition ratios, film qualities and film thicknesses in aversatile and reproducible manner through the use of one substrateprocessing apparatus or remove the thin films. In addition, it ispossible to reduce an operator's operation burden (for example, burdenof inputting processing procedures, processing conditions, and thelike), and to quickly start the substrate processing process whileavoiding an operation error.

In the embodiments described above, there has been described the examplein which the thin film is formed by using the batch-type substrateprocessing apparatus that processes a plurality of substrates at a time.The present disclosure is not limited to the embodiments describedabove, and may be suitably applied to, for example, a case where a thinfilm is formed by using a single-substrate-type processing apparatusthat processes one or several substrates at a time. Further, in theembodiments described above, there has been described the example inwhich the thin film is formed by the substrate processing apparatusincluding the hot wall type process furnace. The present disclosure isnot limited to the embodiments described above, and may be suitablyapplied to a case where a thin film is formed by using a substrateprocessing apparatus including a cold wall type process furnace. Also inthese cases, the processing conditions may be, for example, the same asthe processing conditions of the embodiments described above.

Further, the embodiments and modifications described above may beappropriately combined and used. Further, the processing conditions atthis time may be, for example, the same as the processing conditions ofthe embodiments described above.

According to the embodiments of the present disclosure, it is possibleto improve a manufacturing throughput of an electronic device or thelike.

The disclosure of Japanese Patent Application No. 2018-031234 isincorporated herein by reference in its entirety.

All documents, patent applications and technical standards mentionedherein are incorporated herein by reference to the same extent as whenthe individual documents, patent applications and technical standardsare specifically and individually described to be incorporated herein.

While certain embodiments have been described, these embodiments havebeen presented by way of example only, and are not intended to limit thescope of the disclosures. Indeed, the embodiments described herein maybe embodied in a variety of other forms. Furthermore, various omissions,substitutions and changes in the form of the embodiments describedherein may be made without departing from the spirit of the disclosures.The accompanying claims and their equivalents are intended to cover suchforms or modifications as would fall within the scope and spirit of thedisclosures.

What is claimed is:
 1. A cleaning method, comprising: removing a depositadhering to an inside of a process container by supplying a cleaning gasinto the process container after performing a process of forming a filmon a substrate in the process container, wherein the act of removing thedeposit includes sequentially and repeatedly performing: a first processof supplying the cleaning gas into the process container until apredetermined first pressure is reached in the process container; asecond process of stopping the supply of the cleaning gas and exhaustingthe cleaning gas and a reaction product generated by the cleaning gasremaining in the process container; and a third process of cooling anexhaust pipe that connects the process container and a vacuum pump,while maintaining a pressure inside the process container at a secondpressure, which is lower than the first pressure, or lower, wherein thethird process continuously performs the act of cooling the exhaust pipeuntil a temperature of the exhaust pipe becomes equal to or lower than afirst temperature, when the temperature of the exhaust pipe at the timeof transition from the second process to the third process is higherthan a second temperature that is higher than the first temperature, andwherein the third process terminates the act of cooling the exhaust pipeat a predetermined time without continuing the act of cooling theexhaust pipe until the temperature of the exhaust pipe becomes equal toor lower than the first temperature, when the temperature of the exhaustpipe is equal to or lower than the second temperature.
 2. The cleaningmethod of claim 1, wherein the third process naturally cools the exhaustpipe by exposing the exhaust pipe to the cleaning gas and the reactionproduct less than in the first process and the second process, andwherein each of the first process and the second process is performed ata predetermined time except for an emergency.
 3. The cleaning method ofclaim 2, wherein the first process includes an operation of exhaustingthe cleaning gas with the vacuum pump to maintain the first pressurewhile continuing to supply the cleaning gas at a constant flow rate,wherein the third process measures the temperature of the exhaust pipeby using a temperature detector installed at the exhaust pipe, whereinthe first process and the third process perform a pressure adjustment byusing a pressure regulator installed at the exhaust pipe, and whereinthe process container includes: a cylindrical portion having a closedupper end portion and an opened lower end portion; a gas supply areaformed outside one side wall of the cylindrical portion and connected toa gas supply system configured to supply the cleaning gas; and a gasexhaust area formed outside the other side wall of the cylindricalportion facing the gas supply area and connected to an exhaust systemconfigured to exhaust an atmosphere in the process container.
 4. Thecleaning method of claim 3, wherein the second temperature is atemperature lower than a temperature at which the exhaust pipe iscorroded.
 5. The cleaning method of claim 4, wherein in the thirdprocess, the exhaust pipe is naturally cooled, or the exhaust pipe isforcibly cooled by supplying an inert gas into the exhaust pipe.
 6. Thecleaning method of claim 1, wherein the first process includes anoperation of exhausting the cleaning gas with the vacuum pump tomaintain the first pressure while continuing to supply the cleaning gasat a constant flow rate, wherein the third process measures thetemperature of the exhaust pipe by using a temperature detectorinstalled at the exhaust pipe, wherein the first process and the thirdprocess perform a pressure adjustment by using a pressure regulatorinstalled at the exhaust pipe, and wherein the process containerincludes: a cylindrical portion having a closed upper end portion and anopened lower end portion; a gas supply area formed outside one side wallof the cylindrical portion and connected to a gas supply systemconfigured to supply the cleaning gas; and a gas exhaust area formedoutside the other side wall of the cylindrical portion facing the gassupply area and connected to an exhaust system configured to exhaust anatmosphere in the process container.
 7. The cleaning method of claim 1,wherein the second temperature is a temperature lower than a temperatureat which the exhaust pipe is corroded.
 8. The cleaning method of claim2, wherein the second temperature is a temperature lower than atemperature at which the exhaust pipe is corroded.
 9. The cleaningmethod of claim 1, wherein in the third process, the exhaust pipe isnaturally cooled, or the exhaust pipe is forcibly cooled by supplying aninert gas into the exhaust pipe.
 10. The cleaning method of claim 2,wherein in the third process, the exhaust pipe is naturally cooled, orthe exhaust pipe is forcibly cooled by supplying an inert gas into theexhaust pipe.
 11. The cleaning method of claim 3, wherein in the thirdprocess, the exhaust pipe is naturally cooled, or the exhaust pipe isforcibly cooled by supplying an inert gas into the exhaust pipe.
 12. Thecleaning method of claim 1, wherein the cleaning gas is a mixed gas of afluorine gas and a nitric oxide gas, and wherein the deposit is asilicon oxycarbonitride film.
 13. The cleaning method of claim 2,wherein the cleaning gas is a mixed gas of a fluorine gas and a nitricoxide gas, and wherein the deposit is a silicon oxycarbonitride film.14. The cleaning method of claim 3, wherein the cleaning gas is a mixedgas of a fluorine gas and a nitric oxide gas, and wherein the deposit isa silicon oxycarbonitride film.
 15. A method of manufacturing asemiconductor device, comprising: removing a deposit adhering to aninside of a process container by supplying a cleaning gas into theprocess container; and performing a process of forming a film on asubstrate in the process container, wherein the act of removing thedeposit includes sequentially and repeatedly performing: a first processof supplying the cleaning gas into the process container and exhaustingthe cleaning gas with a vacuum pump to maintain a predetermined firstpressure in the process container; a second process of stopping thesupply of the cleaning gas and exhausting the cleaning gas and areaction product generated the cleaning gas remaining in the processcontainer; and a third process of cooling an exhaust pipe that connectsthe process container and the vacuum pump, while maintaining a pressureinside the process container at a second pressure, which is lower thanthe first pressure, or lower, wherein the third process continuouslyperforms the act of cooling the exhaust pipe until a temperature of theexhaust pipe becomes equal to or lower than a first temperature, whenthe temperature of the exhaust pipe at the time of transition from thesecond process to the third process is higher than a second temperaturethat is higher than the first temperature, and wherein the third processterminates the act of cooling the exhaust pipe at a predetermined timewithout continuing the act of cooling the exhaust pipe until thetemperature of the exhaust pipe becomes equal to or lower than the firsttemperature, when the temperature of the exhaust pipe is equal to orlower than the second temperature.
 16. A substrate processing apparatus,comprising: a process container configured to accommodate a substratetherein; a film-forming gas supply system configured to supply afilm-forming gas to the substrate in the process container; a cleaninggas supply system configured to supply a cleaning gas into the processcontainer; a connector configured to connects an exhaust pipe configuredto evacuate an inside of the process container and the processcontainer; and a controller configured to control the film-forming gassupply system and the cleaning gas supply system so as to perform aprocess of forming a film by supplying the film-forming gas to thesubstrate in the process container and a process of removing a depositadhering to the inside of the process container by supplying thecleaning gas into the process container, wherein the process of removingthe deposit includes sequentially and repeatedly performing: a firstprocess of supplying the cleaning gas into the process container andexhausting the cleaning gas with a vacuum pump to maintain apredetermined first pressure in the process container; a second processof stopping the supply of the cleaning gas and exhausting the cleaninggas and a reaction product generated by the cleaning gas remaining inthe process container; and a third process of cooling the exhaust pipethat connects the process container and the vacuum pump, whilemaintaining a pressure inside the process container at a secondpressure, which is lower than the first pressure, or lower, wherein thethird process continuously performs the act of cooling the exhaust pipeuntil a temperature of the exhaust pipe becomes equal to or lower than afirst temperature, when the temperature of the exhaust pipe at the timeof transition from the second process to the third process is higherthan a second temperature that is higher than the first temperature, andwherein the third process terminates the act of cooling the exhaust pipeat a predetermined time without continuing the act of cooling theexhaust pipe until the temperature of the exhaust pipe becomes equal toor lower than the first temperature, when the temperature of the exhaustpipe is equal to or lower than the second temperature.
 17. The substrateprocessing apparatus of claim 16, wherein the process containerincludes: a cylindrical portion having a closed upper end portion and anopened lower end portion; a gas supply area formed outside one side wallof the cylindrical portion and connected to a gas supply systemconfigured to supply the cleaning gas; and a gas exhaust area formedoutside the other side wall of the cylindrical portion facing the gassupply area and connected to an exhaust system configured to exhaust anatmosphere in the process container, and wherein each of the gas supplyarea and the gas exhaust area includes an inner wall that divides aninternal space thereof into a plurality of spaces.
 18. The substrateprocessing apparatus of claim 17, wherein a gas supply hole configuredto supply the cleaning gas into the cylindrical portion is formed at aboundary wall between the gas supply area and the cylindrical portion.19. The substrate processing apparatus of claim 18, wherein a gasexhaust hole configured to exhaust an atmosphere in the cylindricalportion is formed at a boundary wall between the gas exhaust area andthe cylindrical portion.
 20. The substrate processing apparatus of claim19, wherein the gas supply hole and the gas exhaust hole are formed in aplural number in a vertical direction at positions facing each of theplurality of spaces.